Coulombe fired a scoreless eighth inning in Tuesday's 4-1 loss to the Rangers.
He breezed through the potent trio of Joey Gallo, Elvis Andrus and Adrian Beltre on six pitches, giving him three scoreless efforts to open the season. The 28-year-old southpaw could see a workload akin to the career-high 72 appearances he logged in 2017, given the scarcity of his handedness in the Athletics' relief corps.